	US 12,233,167 B2
	Bio-compatible polyurethane microcapsules and process for the preparation thereof
Nilakshi Vaibhav Sadavarte, Pune (IN); Kadhiravan Shanmuganathan, Pune (IN); and Parshuram Gajanan Shukla, Pune (IN)
Assigned to Council of Scientific & Industrial Research, New Delhi (IN)
Appl. No. 17/601,583
Filed by COUNCIL OF SCIENTIFIC & INDUSTRIAL RESEARCH, New Delhi (IN)
PCT Filed Mar. 27, 2020, PCT No. PCT/IN2020/050289 § 371(c)(1), (2) Date Oct. 5, 2021, PCT Pub. No. WO2020/202187, PCT Pub. Date Oct. 8, 2020.
Claims priority of application No. 201911013812 (IN), filed on Apr. 5, 2019.
Prior Publication US 2022/0202731 A1, Jun. 30, 2022
Int. Cl. A61K 9/50 (2006.01); A01N 25/10 (2006.01); A01N 25/28 (2006.01); A01N 37/10 (2006.01); A01N 37/18 (2006.01); A01N 43/70 (2006.01); A01N 47/30 (2006.01); A61K 9/48 (2006.01); A61K 31/11 (2006.01); A61K 31/192 (2006.01); A61K 31/555 (2006.01); B01J 13/16 (2006.01)

CPC A61K 9/5031 (2013.01) [A01N 25/10 (2013.01); A01N 25/28 (2013.01); A01N 37/10 (2013.01); A01N 37/18 (2013.01); A01N 43/70 (2013.01); A01N 47/30 (2013.01); A61K 9/4866 (2013.01); A61K 9/5089 (2013.01); A61K 31/11 (2013.01); A61K 31/192 (2013.01); A61K 31/555 (2013.01); B01J 13/16 (2013.01)]

10 Claims

1. A partially bio-based polyurethane microcapsule for sustained release of an active ingredient comprising;

i) a core containing at least one active ingredient selected from the group consisting of dimethyl phthalate, N,N-Diethyl-meta-toluamide (DEET), Ibuprofen, Diuron, Zinc Pyrithione, Irgarol, and 4-Anisaldehyde; and

ii) a bio-compatible polymeric shell consisting of (a) a bio-based aliphatic diol, (b) an aliphatic diisocyanate, (c) a cross linker and (d) an additive; wherein the bio-based aliphatic diol is selected from the group consisting of isosorbide, 1,3-propane diol, 1,4-butane diol, 2,3-butane diol, and 1,6-hexane diol and the aliphatic diisocyanate is selected from the group consisting of 1,6 Hexamethylene diisocyanates (HMDI), Isophorone diisocyanate (IPDI), pentamethylene diisocyanates (PDI), and 4,4′-Diisocyanatodicyclohexylmethane (H₁₂MDI); wherein said additive is selected from the group consisting of nanocellulose, nanoclay, nanosilica and carbon nanotube (CNT);

wherein, the mole ratio of diisocyanate to hydroxyl groups present in aliphatic diol is 1.2:1;

and wherein, the partially bio-based polyurethane microcapsule has an encapsulation efficiency of 70-95%.